If Form 1040A or 1040 works best for you, then you're probably going to have some added tax paperwork to complete, such as Schedule A if you itemize deductions or a variety of work sheets or forms if you claim some credits. Once you determine the extra forms you'll need, you can download them.
Bankrate's Tax Guide has the most common forms ready to download. If you need others or additional instruction books, check out the IRS website.
Gathering the data
Next, track down all your income documents -- W-2 salary and wage statements, reports on how much interest you earned last year.
Don't have them all? Get in touch with your boss and the other statement issuers, and request copies now. If you have to wait for the duplicates, though, make sure you file an extension application.
If you're really committed to getting your taxes done today, there's a way you can file without the forms. For interest and dividend income, pull out your last account statements. They should have the earnings information you need.
As for your missing W-2, use the data on your final pay stub from last year to complete Form 4852, the IRS' authorized income statement substitute. Then, fill out Form 4852 in place of the absent W-2.
Filling in the blanks
Now it's time to fill in the form blanks.
The key here is making sure you don't miss any tax deductions or credits (hint: Credits are usually better since they reduce your tax bill dollar-for-dollar) that can save you some tax dollars.
The bulk of the tax breaks, such as home-related deductions, go to itemizers. But most filers actually claim the standard deduction, and there are some write-offs, such as more than a dozen above-the-line deductions, that are available to every taxpayer, regardless of which deduction method they use.
If you think you might be able to claim some deductions or tax credits but are having trouble finding all those receipts to substantiate your claim, consider filing that extension request so you'll have a few more months to sort through the stack of tax documents in the corner.
The home stretch
Oh, wait! You just found the receipt you needed, so it's time to wrap up this process.
You've completed the forms, attached the required statements, made out the check, affixed your signature and sealed the envelope. Now it's time to get that tax material on its way to the IRS.
If you've done your taxes the old-fashioned paper way, head for the post office. But make sure it's a quick trip. Use the U.S. Postal Service's office locator to find the one nearest you. If it's getting late, call first to make sure the office will be open longer to collect tax returns.
Or you could dispense with paper altogether. You can download several tax software packages and use them to file electronically directly from your personal computer. If you don't want to clutter up your computer's hard drive, you can access essentially the same products online to complete your taxes via the Web. The IRS encourages this method via the Free File Alliance, which affords some taxpayers no-cost online tax prep and filing.